TWI872637B - Sensing control circuit of a range hood and control method thereof - Google Patents

Abstract

A sensing control circuit of a range hood and a control method thereof are provided. The sensing control circuit includes: a sensing circuit and a control circuit. The sensing circuit has a first sensor, a second sensor and a third sensor. The control circuit controls the range hood to perform a functional action according to the sensing result of the sensing circuit. When the sensing results of the control circuit at the first sensor, the second sensor, and the third sensor meet a repetition condition, the control circuit enters a shielding mode, and until the first sensor, the second sensor until the sensing results of the sensor and the third sensor do not meet the repetition condition. When the control circuit ends the shielding mode and the sensing results of the first sensor, the second sensor and the third sensor meet an action setting condition, the control circuit controls the range hood to perform functional operations.

Description

Range hood sensing control circuit and sensing control method thereof

The present invention relates to a range hood, and more particularly to a sensing control circuit and a sensing control method of the range hood.

In addition to being able to directly control the relevant buttons, existing range hood functions such as exhaust speed, lighting function or switch can also be non-contact operated by installing sensors for automatic detection. However, existing sensors are all installed on the front side of the range hood, but this installation location often causes misdetection due to the movement of people passing by, making it impossible for the range hood to accurately perform non-contact operation.

The technical problem to be solved by the present invention is to provide a sensing control circuit and sensing control method for a range hood in view of the deficiencies of the prior art.

The present invention provides a sensing control circuit for a range hood, comprising: a sensing circuit and a control circuit. The sensing circuit has a first sensor, a second sensor and a third sensor; a control circuit is electrically connected to the first sensor, the second sensor and the third sensor respectively, and the control circuit controls the range hood to perform a function operation according to the sensing result of the sensing circuit. When the sensing results of the first sensor, the second sensor and the third sensor meet a repetitive condition, the control circuit enters a shielding mode and continues until the sensing results of the first sensor, the second sensor and the third sensor do not meet the repetitive condition; when the control circuit ends the shielding mode and the sensing results of the first sensor, the second sensor and the third sensor meet an action setting condition, the control circuit controls the range hood to perform the functional operation.

An embodiment of the present invention provides a sensing control method for a range hood, which is applicable to a control circuit that controls the range hood to perform a functional operation based on the sensing results of a sensing circuit of the range hood, including: when the sensing results of a first sensor, a second sensor and a third sensor of the sensing circuit meet a repetitive condition, the control circuit enters a shielding mode and continues until the sensing results of the first sensor, the second sensor and the third sensor do not meet the repetitive condition; and when the control circuit ends the shielding mode and when the sensing results of the first sensor, the second sensor and the third sensor meet an action setting condition, the control circuit controls the range hood to perform the functional operation.

In summary, the sensing control circuit and sensing control method of the range hood provided by the embodiments of the present invention can effectively eliminate false detection, so that the range hood can be operated more accurately in a non-contact manner.

To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only used for reference and description and are not used to limit the present invention.

The following is a specific embodiment to illustrate the implementation of the present invention. The technical personnel in this field can understand the advantages and effects of the present invention from the content provided in this specification. The present invention can be implemented or applied through other different specific embodiments. The details in this specification can also be modified and changed in various ways based on different viewpoints and applications without deviating from the concept of the present invention. In addition, the drawings of the present invention are only for simple schematic illustration and are not depicted according to actual size. Please note in advance. The following implementation will further explain the relevant technical content of the present invention in detail, but the content provided is not intended to limit the scope of protection of the present invention.

It should be understood that, although the terms "first", "second", "third", etc. may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used in this document may include any one or more combinations of the related listed items depending on the actual situation.

The present invention provides a sensing control circuit and sensing control method for a range hood. The sensing control circuit of the range hood described herein is integrated with a target detection function. Through the detection result, it can be known whether someone controls the functional operation of the range hood, for example, through a gesture operation. Specifically, the functional operation of the range hood referred to in this case can be performed in a non-contact manner, and by appropriately setting the number of sensors used in the sensing circuit and the position of the sensors set on the range hood, unnecessary misoperation can be effectively reduced, and it can also not affect the relevant behaviors of existing personnel in cooking actions, so that the range hood can accurately perform relevant functional operations.

[Hardware architecture of the sensor control circuit of the range hood]

Please refer to Figures 1, 2, 3 and 4. Figure 1 is a side view of a range hood provided by an embodiment of the present invention, and Figure 2 is a front view of a range hood provided by an embodiment of the present invention. Figure 3 is a circuit block diagram of a sensing control circuit of a range hood provided by an embodiment of the present invention, and Figure 4 is a waveform diagram of a signal emitted by the sensing circuit provided by an embodiment of the present invention.

Here, the range hood 2 is embedded in the system cabinet 10, and the range hood 2 is internally integrated with a sensing control circuit 20. The sensing control circuit 20 includes, but is not limited to, a control circuit 201 and a sensing circuit 203. The control circuit 201 is electrically connected to the sensing circuit 203. The sensing circuit 203 is, for example, disposed on a bottom surface of the range hood 2 facing the pot, i.e., the sensing direction of the sensing circuit 203. The gas stove 12 is placed downward, and the control circuit 201 includes a plurality of sensors to improve the accuracy of sensing, for example, a first sensor 2031, a second sensor 2033 and a third sensor 2035 are used as examples for illustration, and the first sensor 2031, the second sensor 2033 and the third sensor 2035 are sequentially arranged at intervals on the bottom surface of the range hood 2 and electrically connected to the control circuit 201. Here, the first sensor 2031, the second sensor 2033 and the third sensor 2035 are used as infrared sensors for illustration, but the present invention is not limited thereto.

In one embodiment, the sensing ranges of the sensors in the sensing circuit 203 are not the same. As shown in FIG. 2 , the transmission signal strengths of the first sensor 2031 and the third sensor 2035 are greater than the transmission signal strength of the second sensor 2033. Therefore, the sensing distance and range of the first sensor 2031 and the third sensor 2035 are greater than the sensing distance and range of the second sensor 2033. Here, the dashed area below each sensor is represented as the sensing range.

In one embodiment, as shown in FIG. 4 , the frequency of the signals transmitted by the first sensor 2031 and the third sensor 2035 is greater than the frequency of the signals transmitted by the second sensor. For example, the frequency of the signals transmitted by the first sensor 2031 and the third sensor 2035 may be approximately twice or more than the frequency of the signals transmitted by the second sensor 2033. For example, the transmission angle of the signals transmitted by each sensor is, for example, +20 degrees/-20 degrees, the spacing distance between each sensor is, for example, 11.5 centimeters, and the intersection point of the signals transmitted by each sensor is, for example, approximately 15.78 centimeters. However, the present invention is not limited thereto, and the relevant parameters of the sensors may be flexibly changed according to the setting requirements.

Specifically, the control circuit 201 is electrically connected to the first sensor 2031, the second sensor 2033 and the third sensor 2035 respectively. The control circuit 201 controls the range hood 2 to perform a functional operation according to the sensing result of the sensing circuit 203. This functional operation includes but is not limited to controlling the range hood 2 to increase or decrease the exhaust speed, start or shut down, or turn on or off the lighting.

In one embodiment, in order to effectively avoid noise interference (such as environmental noise), the control circuit 201 can shield the noise by executing a shielding mode. For example, when the control circuit 201 executes in the shielding mode, the sensing result of the sensing circuit 203 is considered to be invalid environmental noise. The source of this environmental noise may be a stationary object, such as a pot placed on the gas stove 12. Since the placed pot is stationary for a long time, it will not be recognized as a normal gesture operation by the control circuit 201.

Here, the control circuit 201 decides whether to enter the shielding mode based on the sensing results of the sensing circuit 203. For example, when the sensing results of the first sensor 2031, the second sensor 2033 and the third sensor 2035 of the control circuit 201 meet a repetition condition, the control circuit 201 can enter a shielding mode and will not exit the shielding mode until the sensing results of the first sensor 2031, the second sensor 2033 and the third sensor 2035 do not meet the repetition condition.

It should be noted that the repetitive condition described herein is, for example, that the first sensor 2031, the second sensor 2033, and the third sensor 2035 all receive a repetitive sensing signal that lasts for a first preset time, and the repetitive signal is, for example, environmental noise generated by placing a pot on the aforementioned gas stove 12. The control circuit 201 determines whether to terminate the shielding mode in a manner such as that the sensing signal received by any one of the first sensor 2031, the second sensor 2033, and the third sensor 2035 is different from the sensing signal received in the shielding mode.

It should also be noted that the second sensor 2033 in FIG. 4 transmits a signal in a manner of resting after transmitting once, but the first sensor 2031 and the third sensor 2035 transmit signals continuously. In other words, the first sensor 2031 and the third sensor 2035 can receive the rebound signal transmitted by themselves and meet the repetitive conditions required to enter the shielding mode. However, if the second sensor 2033 receives the rebound signal transmitted by itself, it cannot meet the repetitive conditions required to enter the shielding mode because the signal transmitted by the second sensor 2033 is not continuously transmitted. However, the second sensor 2033 can still meet the repetitive conditions required to enter the shielding mode by receiving the rebound signal transmitted by the first sensor 2031 or the third sensor 2035.

In one embodiment, when the control circuit 201 is in the end shielding mode and the sensing results of the first sensor 2031, the second sensor 2033 and the third sensor 2035 meet an action setting condition, the control circuit 201 can control the range hood 2 to perform a corresponding functional operation.

For example, the action setting condition may include but is not limited to a first action setting condition, a second action setting condition and a third action setting condition, wherein the first action setting condition is, for example, that the first sensor 2031, the second sensor 2033 and the third sensor 2035 receive the sensing signal in sequence; the second action setting condition is, for example, that the third sensor 2035, the second sensor 2033 and the first sensor 2031 receive the sensing signal in sequence; the third action setting condition is, for example, that the first sensor 2031 and the third sensor 2035 maintain the same sensing signal as that received in the shielding mode, and the second sensor 2033 continues to receive the sensing signal for a second preset time. The action setting condition is merely an example, but the present invention is not limited thereto.

Here, the first action setting condition is used to determine whether there is a target object moving in a first moving direction under the sensing circuit 203, the second action setting condition is used to determine whether there is a target object moving in a second moving direction under the sensing circuit 203, and the third action setting condition is used to determine whether there is a target object performing a long trigger function operation under a specific sensor in the sensing circuit 203.

It is worth noting that the sensing signal continuously received by the second sensor 2033 during the second preset time is a rebound signal received by the second sensor 2033 after transmitting a signal and hitting a target object, that is, the target object is located within the sensing range SA2 of the second sensor 2033 at this time, and the target object also blocks the second sensor 2033 from receiving the rebounded transmission signal of the first sensor 2031 or the third sensor 2035. On the other hand, the sensing signal continuously received by the second sensor 2033 during the first preset time is a rebound signal received by the first sensor 2031 or the third sensor 2035 after transmitting a signal and hitting a stationary object, that is, there is no object within the sensing range SA2 of the second sensor 2033 at this time.

In one embodiment, the control circuit 201 is electrically connected to the exhaust circuit 205 and the lighting circuit 207 in the range hood 2. The exhaust circuit 205 is mainly used to control the exhaust speed of the range hood 2, and the lighting circuit 207 has at least one lighting lamp that can be used to control the lighting function of the range hood 2. The control circuit 201 can control the exhaust circuit 205 or the lighting circuit 207 according to the sensing result of the sensing circuit 203 and when the sensing result meets the specific action setting condition, the control circuit 201 can control the exhaust circuit 205 or the lighting circuit 207 according to the corresponding function operation of the specific action setting condition.

[Sensing control method of range hood]

Please refer to FIG5. FIG5 is a control flow chart of a range hood sensing control method provided by an embodiment of the present invention. The flow chart shown in FIG5 is used as an example to illustrate the structure of FIG1 to FIG3, but is not limited thereto. The process shown in FIG5 includes the following steps, for example.

In step S501, a sensing signal is detected. Here, the control circuit 201 can obtain the sensing signal through the detection result of the sensing circuit 203, for example, the first sensing signal is obtained by the first sensor 2031, the second sensing signal is obtained by the second sensor 2033, and the third sensing signal is obtained by the third sensor 2035.

In step S503, it is determined whether the repetition condition is met. Here, the control circuit 201 determines whether the repetition condition is met according to the multiple sensing signals obtained by each sensor in the sensing circuit 203. For example, it is determined whether the first sensing signal obtained by the first sensor 2031, the second sensing signal obtained by the second sensor 2033, and the third sensing signal obtained by the third sensor 2035 are all received repetition signals that last for a first preset time.

In step S505, the shielding mode is entered. When step S503 is judged as yes, it means that the first sensor 2031, the second sensor 2033 and the third sensor 2035 have all received the repeated signal that lasts for the first preset time, and the control circuit 201 will enter the shielding mode operation at this time. In the shielding mode, the control circuit 201 will temporarily shield the data received by each sensor in the sensing circuit 203 until the shielding mode is terminated.

In step S507, it is determined whether to terminate the shielding mode. Here, the control circuit 201 determines whether the sensing result of the sensing circuit 203 no longer meets the repetition condition as a basis for whether to terminate the shielding mode. For example, when the sensing signal received by any one of the first sensor 2031, the second sensor 2033 and the third sensor 2035 generates a signal change, that is, the sensing signal received at this time is different from the continuous repetitive sensing signal received in the shielding mode, the control circuit 201 can terminate the operation of the shielding mode. When step S507 determines that it is not, step S507 is continued.

In step S509, it is determined whether the action setting condition is met. When step S507 is determined to be yes, the control circuit 201 determines whether the sensing result of the sensing circuit 203 meets the preset action setting condition, for example, the action setting condition is related to the movement mode of the target object or the duration of the target object at a specific placement position.

In step S511, the function operation is performed. When step S509 is judged as yes, the control circuit can control the range hood to perform the function operation corresponding to the action setting condition. This function operation is based on the corresponding judgment that the action setting condition is met. When step S509 is judged as no, it returns to step S501.

In one embodiment, the repetitive condition in step S503 can refer to FIG. 6 which is a waveform diagram of the sensing signals received by each sensor. It can be clearly seen from the time T1 in FIG. 6 that the first sensor 2031, the second sensor 2033 and the third sensor 2035 all receive continuously repeated sensing signals. The reason for this is that the sensing circuit 203 senses a stationary object. For example, when a pot is placed on the gas stove 12, the sensing result shown in FIG. 6 will be presented. It should also be specially explained that the sensing signals received by the first sensor 2031 and the third sensor 2035 are both received when the sensing signals emitted by the first sensor 2031 and the third sensor 2035 hit a stationary object and bounce back. However, the second sensor 2033 is limited by its own sensing range SA2 which is smaller than the sensing ranges SA1 and SA3 of the first sensor 2031 and the third sensor 2035 (see FIG. 2 ). Therefore, the sensing signal received by the second sensor 2033 is a bounce signal received when the sensing signals emitted by the first sensor 2031 and the third sensor 2035 hit a stationary object and bounce back.

In addition, the control circuit 201 in FIG6 determines that each sensor has continuously received a first preset time at time T1, and then enters the shielding mode operation. The first preset time is, for example, 1 second, but the present invention is not limited thereto. In the shielding mode operation, the control circuit 201 will temporarily shield the data received by each sensor, for example, after time T2 in FIG6, each sensor will stop receiving signals.

In one embodiment, the action setting condition in step S509 is, for example, a first action setting condition that the target moves in a specific moving direction within the sensing range of the sensing circuit 203. For example, the target in FIG. 7a is a hand, and the hand moves in the first moving direction D1 within the sensing range of each sensor in the sensing circuit 203, in sequence from the sensing range SA1 of the first sensor 2031, the sensing range SA2 of the second sensor, and the sensing range SA3 of the third sensor. At this time, the sensing signal received by the control circuit 201 through the sensing circuit 203 can be as shown in FIG. 7b, that is, the first sensor 2031, the second sensor 2033, and the third sensor 2035 receive the sensing signal in sequence, and then the control circuit 201 can control the range hood 2 to perform the first functional operation corresponding to the first action setting condition.

Similarly, the action setting condition in step S509 may also be a second action setting condition that the target moves in a specific moving direction within the sensing range of the sensing circuit 203. For example, the hand moves in the sensing range of each sensor in the sensing circuit 203 in the second moving direction D2 in sequence within the sensing range SA3 of the third sensor 2035, the sensing range SA2 of the second sensor 2033, and the sensing range SA1 of the first sensor 2031. At this time, the sensing signal received by the control circuit 201 through the sensing circuit 203 is the sensing signal received in sequence by the third sensor 2035, the second sensor 2033, and the first sensor 2031, and then the control circuit 201 can control the range hood 2 to perform the second function operation corresponding to the second action setting condition.

In one embodiment, the action setting condition in step S509 is, for example, a third action setting condition that the target object is sensed for a long time by a specific sensor of the sensing circuit 203. For example, the target object in FIG8a is a hand, and the hand is within the sensing range SA2 of the second sensor 2033 in the sensing circuit 203. At this time, the sensing signal received by the control circuit 201 through the sensing circuit 203 may be as shown in FIG8b, that is, the first sensor 2031 and the third sensor 2035 do not receive the sensing signal, and only the second sensor 2033 receives the sensing signal, and when the control circuit 201 determines that the second sensor 2033 receives the sensing signal and continues to receive the sensing signal for more than the second preset time, the control circuit 201 can then control the range hood 2 to perform the third function operation corresponding to the third action setting condition.

In one embodiment, when the target object moves to the lower position in the sensing circuit 203, as shown in FIG. 9 , the target object is a hand, and the hand moves directly from the sensing range SA1 of the first sensor 2031 to the sensing range SA3 of the third sensor 2035, but the hand does not pass through the sensing range SA2 of the second sensor 2033. At this time, the control circuit 201 can know through the sensing result of the sensing circuit 203 that it does not meet any action setting conditions, and judges that it belongs to a cooking action. Therefore, the control circuit 201 will not control the range hood 2 to perform any functional operation, thereby effectively eliminating the interference caused by a simple cooking action.

In one embodiment, each sensor may have different data groups in the signal it transmits, so that each sensor can identify whether the data group in the sensing signal is the data it transmits after receiving the sensing signal. In other words, each sensor can know whether it is the signal it transmits or the signal transmitted by other sensors after receiving the sensing signal.

In one embodiment, the control circuit 201 may be, for example, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a system on a chip (SOC), or any combination thereof, and may cooperate with other related circuit elements and firmware to implement the above functional flow.

[Beneficial Effects of Embodiments]

The sensing control circuit and sensing control method of the range hood provided by the present invention can effectively avoid the misdetection of the reflected signal of a stationary object or a gas stove countertop by executing the shielding mode; and can also effectively eliminate the misoperation of the non-operating range hood by arranging the sensing range of the sensor in strong and weak order. The present invention can thereby accurately control the relevant functional operation of the range hood in a non-contact manner.

The contents provided above are only preferred feasible embodiments of the present invention and are not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the specification and drawings of the present invention are included in the scope of the patent application of the present invention.

10: System cabinet 12: Gas stove 2: Range hood 20: Sensing control circuit 201: Control circuit 203: Sensing circuit 2031: First sensor 2033: Second sensor 2035: Third sensor 205: Exhaust circuit 207: Lighting circuit SA1, SA2, SA3: Sensing range D1: First moving direction D2: Second moving direction S501: Sensing signal detected S503: Meet the repetition condition S505: Enter shielding mode S507: Exit shielding mode S509: Meet the action setting condition S511: Execute function operation

FIG. 1 is a side view of a range hood according to an embodiment of the present invention.

FIG. 2 is a front view of a range hood according to an embodiment of the present invention.

FIG3 is a circuit block diagram of a sensing control circuit for a range hood according to an embodiment of the present invention.

FIG. 4 is a waveform diagram of a signal emitted by a sensing circuit according to an embodiment of the present invention.

FIG5 is a control flow chart of the sensing control method of the range hood according to the embodiment of the present invention.

FIG6 is a waveform diagram showing a sensing signal repeatedly received by the sensing circuit.

FIG. 7a is a schematic diagram showing the sensing circuit detecting a correct hand slide.

FIG. 7 b is a waveform diagram showing the sensing signal received by the sensing circuit in FIG. 7 a .

FIG8a is a schematic diagram showing a sensing circuit sensing a hand trigger.

FIG8b is a waveform diagram showing the sensing signal received by the sensing circuit in FIG8a.

FIG. 9 is a schematic diagram showing an incorrect hand slide detected by the sensing circuit.

10: System cabinet

2: Range hood

2031: First sensor

2033: Second sensor

2035: Third sensor

SA1, SA2, SA3: Sensing range

Claims (10)

A sensing control circuit for a range hood, comprising: a sensing circuit, the sensing circuit detects a target object and has a first sensor, a second sensor and a third sensor arranged in sequence, the sensing distance and range of the first sensor and the third sensor being greater than the sensing distance and range of the second sensor; and a control circuit, electrically connected to the first sensor, the second sensor and the third sensor, respectively, the control circuit controls the range hood to perform a functional operation according to the sensing result of the sensing circuit; When the sensing results of the first sensor, the second sensor and the third sensor meet a repetitive condition, the control circuit enters a shielding mode until the sensing results of the first sensor, the second sensor and the third sensor do not meet the repetitive condition; When the control circuit ends the shielding mode and the sensing results of the first sensor, the second sensor and the third sensor meet an action setting condition of the target object, the control circuit controls the range hood to perform the functional operation. A sensing control circuit for a range hood as described in claim 1, wherein after the control circuit enters the shielding mode, the sensing result of the sensing circuit is determined to be invalid environmental noise, and the sensing circuit is arranged on a bottom surface of the range hood facing the cooker, and the first sensor, the second sensor and the third sensor are arranged on the bottom surface in sequence and at intervals. A sensing control circuit for a range hood as described in claim 2, wherein the repetitive condition is that the first sensor, the second sensor and the third sensor all receive a repetitive sensing signal that lasts for a first preset time, and the control circuit ends the shielding mode when the sensing signal received by any one of the first sensor, the second sensor and the third sensor is different from the sensing signal received in the shielding mode. A sensing control circuit for a range hood as described in claim 3, wherein the action setting condition includes at least one of a first action setting condition, a second action setting condition and a third action setting condition, the first action setting condition is that the first sensor, the second sensor and the third sensor receive sensing signals in sequence, the second action setting condition is that the third sensor, the second sensor and the first sensor receive sensing signals in sequence, the third action setting condition is that the first sensor and the third sensor maintain the same sensing signal as that received in the shielding mode, and the second sensor continues to receive the sensing signal for a second preset time. The sensing control circuit of the range hood as claimed in claim 4, wherein the frequency of the signal transmitted by the first sensor and the third sensor is greater than the frequency of the signal transmitted by the second sensor, the intensity of the signal transmitted by the first sensor and the third sensor is greater than the intensity of the signal transmitted by the second sensor, and the sensing signal received by the second sensor continuously within the second preset time is the second sensor itself The bounce signal received after the signal is transmitted and then hits a target object and then bounces back, and the sensing signal received by the second sensor continuously for the first preset time is the bounce signal received after the signal is transmitted by the first sensor or the third sensor and then hits a stationary object and then bounces back, and the range hood performs the function operation to control the range hood to increase the exhaust speed, decrease the exhaust speed, turn on, turn off, or turn on or off the lighting. A sensing control method for a range hood is applicable to a control circuit that controls the range hood to perform a functional operation according to a sensing result of a sensing circuit of the range hood, including: When the sensing circuit detects a target object and the sensing results of a first sensor, a second sensor and a third sensor arranged in sequence meet a repetitive condition, the control circuit enters a shielding mode until the sensing results of the first sensor, the second sensor and the third sensor do not meet the repetitive condition; and When the control circuit ends the shielding mode and the sensing results of the first sensor, the second sensor and the third sensor meet an action setting condition of the target object, the control circuit controls the range hood to perform the functional operation; The sensing distance and range of the first sensor and the third sensor are greater than the sensing distance and range of the second sensor. A sensing control method for a range hood as described in claim 6, wherein after the control circuit enters the shielding mode, the control circuit determines that the sensing result of the sensing circuit is invalid environmental noise, and the control circuit temporarily shields the sensing signal received from the sensing circuit, wherein the sensing circuit is arranged on a bottom surface of the range hood facing the pot, and the first sensor, the second sensor and the third sensor are arranged on the bottom surface in sequence and at intervals. A sensing control method for a range hood as described in claim 7, wherein the repetitive condition is that the first sensor, the second sensor and the third sensor all receive a repetitive sensing signal that lasts for a first preset time, and the control circuit ends the shielding mode when the sensing signal received by any one of the first sensor, the second sensor and the third sensor is different from the sensing signal received in the shielding mode. A sensing control method for a range hood as described in claim 8, wherein the action setting condition includes at least one of a first action setting condition, a second action setting condition and a third action setting condition, the first action setting condition is that the first sensor, the second sensor and the third sensor receive sensing signals in sequence, the second action setting condition is that the third sensor, the second sensor and the first sensor receive sensing signals in sequence, the third action setting condition is that the first sensor and the third sensor maintain the same sensing signal as that received in the shielding mode, and the second sensor continues to receive the sensing signal for a second preset time. The sensing control method of the range hood as claimed in claim 9, wherein the frequency of the signal transmitted by the first sensor and the third sensor is greater than the frequency of the signal transmitted by the second sensor, the intensity of the signal transmitted by the first sensor and the third sensor is greater than the intensity of the signal transmitted by the second sensor, and the sensing signal received by the second sensor continuously within the second preset time is the second sensor itself The bounce signal received after the signal is transmitted and then hits a target object and then bounces back, and the sensing signal received by the second sensor continuously for the first preset time is the bounce signal received after the signal is transmitted by the first sensor or the third sensor and then hits a stationary object and then bounces back, and the range hood performs the function operation to control the range hood to increase the exhaust speed, decrease the exhaust speed, turn on, turn off, or turn on or off the lighting.

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